Former Assistant Chief Constable James Hobson was said to have never lost interest in the case even in retirement.

2

2

He took over the “toxic” police investigation in 1980, about a year before serial killer Peter Sutcliffe’s arrest for murdering 13 women.

Mr Hobson, played by Lee Ingleby in recent ITV drama The Long Shadow, had controversially suggested some victims were less valuable than others.

He said after the murder of 16-year-old shop assistant Jayne MacDonald that the suspect “hates prostitutes”.

He then warned: “But the Ripper is now killing innocent girls.” Known as Jim, he died on December 12 in Leeds following gall-bladder complications.

His grandson Franco Pardini said: “My grand-father was an old-fashioned, stiff-upper-lip kind of man. You didn’t mess with him.”

Franco said the investigation was “a worrying time”, adding: “He had a daughter at the time — my mum — who was young and going out and had a boyfriend – who is now my dad.

“At one point the police stopped my mum and dad and one of the officers said, ‘Who wants to tell the boss we’ve stopped his daughter with a gentleman we don’t know?’”

He said in his later years he would read anything published about Sutcliffe, but was unhappy with The Long Shadow because there was “a lot of artistic licence and mistakes”.

However Franco revealed he was especially proud of his time in the Royal Navy, in which he served alongside Prince Philip.

Following the death of his wife in 2010, he moved to Roundhay, Leeds, to be nearer his daughter.

He had two great-grandchildren.